Traction-control is an important aspect of automotive functionality. Many all-wheel-drive (AWD) systems utilize a controlled center coupling that is designed to progressively engage the AWD system and therefore control front-to-rear torque distribution. The normally non-driven axle, referred to as a secondary axle, can be fully locked to the driven axle, referred to as a primary axle. The non-driven axle can be disengaged from the driven axle or partially engaged to the driven axle as well.
Unfortunately, AWD systems are still susceptible to side-to-side wheel spin, on each axle. Side-to-side wheel spin occurs when one wheel on an axle looses traction while the other wheel retains traction. Additionally, AWD systems are still susceptible to all-wheel spin-up. All-wheel spin-up occurs when all wheels of the AWD system loose traction and exceed vehicle speed as a group. Both situations present an undesirable control environment for the AWD system.
It would be desirable, therefore, to provide a system that would overcome these and other disadvantages.